Shake or Vibration Issues

[polarys425]

Anyone else notice that a full tank of gas and slightly colder weather improved the vibration? I'm beginning to think that mine be related to the rear drive shaft, diff or pinion angle?

 

Mine, a slight vibration at 72-78 ish, seems improved with a full tank and/or weight in the bed. Back in the spring, it seems as if it also preferred warmer temps. However, I have leveled with fox coil overs up front, so it remains to be seen what cooler temps bring. I've also noticed that a full throttle episode getting on the interstate seems to increase the 75 vibe a bit. I do agree that it seems pinion angle or rear ends are involved in at least some cases.

 

Prior to all that I had vibes in the 45 range as well. I haven't felt those in quite some time.

[Willyone]

When I 1st start off in the morning, or whenever, my '16 Z71 gets a vibe or something, at around 45. Feels like it might be a "flat spot" in a tire or maybe two? I'm not sure. Anyways it seems to go away after driving a couple of miles. The 70+ mph vibration is always there...pisses me right off.

[abominable z71]

 

Time to start thinking outside the box since GM isn't and the same thing over and over is being tried by dealerships to no avail... I'm tired of reading about road force balances and driveshaft balance/replacements not fixing the problem. They've been trying the same thing for 3 years...what's the definition of insanity again?

 

I've got the 65-80 mph vibration. It starts faintly at 65, peaks at 75 and fades away to 80 and is fairly smooth after that, although it isn't perfect. I can feel it mostly in the floor/seat, and only a little bit in the steering wheel. The jump seat armrest shakes pretty bad, it will visibly shake a drink but I don't think it would spill it. I have a 2016 2WD CC SLE Sierra with the OEM 20" wheels and tires. The vibration occurs regardless of what gear the truck is in, neutral included, and V4 mode doesn't affect it either. In theory this means that there should be no issue with any drivetrain component in front of the diff. EDIT: this is wrong out of context. Driveshaft and diff components could also be the source, but these would be 2nd order vibrations. Below, I determine that I have a 1st order vibration so that rules these components out.)

 

I've used the VibSensor Android app to measure the frequency of the vibrations from 65-80 mph, meaning I've recorded multiple 60 second samples at various consistent speeds in that range. The tests all show a strong ~10-14Hz response depending on the speed. I've placed my phone on the armrest, floor, and dash with all similar results, the only change being the magnitude of the frequency. This frequency should point to a 1st order vibration.

 

With all of that said, we should be looking at all things that could cause a first order vibration regardless of engine speed. My gut tells me that the problem lies somewhere in the wheel assembly, although a side bearing, cup, or shim could be the issue. Even still, with as elusive as this problem has been, it could be an out of balance radio knob

 

To start diag of a 1st order vibration #PI1354C is actually the beginnings of a great bulletin, but for some reason GM stops diag and resolution after balancing the tires. Let's look at all the possible things that could cause a 1st order vibration below. Remember, runout can be radial or lateral.

• Tire balance
• Tire runout
• Wheel runout
• Tire uniformity/road force variation
• Incorrect mounting
• Rotor balance/runout (not warping)
• Rear axle shaft/"hub" runout
• Front hub runout
• Wheel stud runout
• Bearing runout

I'm sure there's potentially others, but that at least covers a lot more than a road force balance. The most efficient way to diag all of this at home is to simply measure the runout and go from there, that way we're not just throwing parts and money at the problem. The Hunter GSP9700 will take care of the first 5 things to a certain extent. Placement of the tire on the wheel can help with runout to a point, and the machine will also alert the technician if the wheel wasn't mounted correctly, although this doesn't help when actually mounting on the car. I don't have the tools or time to measure runout of the other components, but I'm considering tackling it if no one here can easily do it. I realize we'll need many samples though.

 

Once it has been confirmed that there isn't any excessive runout to any component, the other major vibration source is balance. The GSP9700 takes care of the wheels and tires which leaves the rotor as the only other thing that can be individually balanced (more on balancing the entire assembly as a whole later). Yes, there is such thing as balancing a rotor. No, I'm not talking about warping. Yes, I know that this is very uncommon. All reputable brake companies balance their rotors during manufacturing, however, I've come across many stories of OEM and even top aftermarket brake companies shipping extremely out of balance rotors. If GM's source has poor QA there could be many trucks with out of balance rotors. Find a machine shop that will check and balance your rotors.

 

Finally, if you still have a vibration after confirming that runout is within tolerances, the tires and rotors are balanced, and road force variation has been corrected...balancing the entire assembly as a whole should be the next step. All of the "fixes" above are just band-aids. There is no such thing as a perfectly balanced and perfectly round component. So the natural frequency of any individually balanced or "rounded" (runout within tolerance) component can be exacerbated when installed with all of the other imperfect components that make up the assembly. What I mean is that stud runout for example can actually make it appear as if you have wheel/tire runout and you'll feel the same vibrations as if your wheel/tire actually had that runout itself. If bad enough, you'll feel the vibration. (and if you have multiple components that are bad enough it could be that the result would be a much higher order vibration and harder to diagnose) To attempt to put a band-aid on this, there's two popular options: on car balancing or a dynamic balancing solution like what Centramatic offers. But again, you have to hope that the amount of runout is small enough that the balance can compensate for it, or hopefully it's a true balance issue that is correctable.

 

This entire theory also explains why there is such a wide variety of owners who have vibrations at different speeds and coming from different locations. smcgillis10 just recently fixed his vibration after replacing his drivers front hub assembly. My guess is he had bearing, stud, or hub runout that was bad enough any sort of balance never could fully compensate for it. This theory also requires that owners not read smcgillis10's solution and replace their drivers front hub assembly. That wouldn't do them any good if the out of spec component is in an assembly on any other other 3 wheels. Being that vibrations seem to be coming from the front or the rear, 2WD or 4WD, is another reason that I believe the issue must be coming from a wheel assembly component and not the driveshaft, transmission, pinion, u-joint, torque converter, or any of the other sources that are being looked at.

 

This was mostly me putting together my thoughts on the issue so that I can begin my own troubleshooting on my truck, but I hope that some of you find it useful, or that it sparks some new thoughts here other than the same thing over and over for 600+ pages. Also, please let me know if any of my logic above isn't sound or if you can expand on any of my thoughts.

 

Here are some links I referenced while putting together these thoughts:

• http://autoguide.com.vsassets.com/blog/wp-content/uploads/2016/03/PI1354C-GM-Truck-Vibration-Information-Bulletin-1.pdf
• http://www.barrystiretech.com/unifandbal.html
• https://www.youtube.com/user/WeberAuto/search?query=runout
• http://www.g-w.com/pdf/sampchap/9781605252131_ch16.pdf

 

Everything listed here has been brought up in the past as well. Somewhere in the 650 pages of posts. I personally brought up all the same points and measured runout on everything. Found runout issues with the hub stud center but at the time new hub assemblies were not readily available and were expensive. To fix the front runout issues requires a complete new assembly to fix the rear requires new axle shafts and I couldn't convince myself to spend the money for one reason, The hubs are not lug centric and the wheels center on the pilot which I found to be right on the money however what is strange GM used lug centric style lug nuts that will pull the wheel in one direct but only as far as the clearance between the rim and pilot will allow. i keep coming back to the hubs as well but haven't convinced myself to replace them because I'm not sure a new assembly will have any better tolerances than the ones on the truck right now. For the rear I looked at new shafts from Yukon 275 dollars each plus the labor to open the diff and unclip them which also means new gear oil making the whole endeavor somewhat expensive and time consuming. Attached is picture I took after measuring runout. The green line is the high point for the stud circle at .010" I used my mititoyo dial indicator with .0005" resolution to make the measurements. If you look closely you will see a pink line right next to the green, that pink line was there from the factory. This tells me GM knows these trucks are sensitive and shake and they are trying to minimize it before it leaves the factory by finding runout and trying to match low spots on the wheel assembly with the high spots on the hub to minimize the overall assembly runout. I'd be interested to know what you find if you measure yours and if you ultimately change hubs if it fixes the issue. Good luck. BTW I used the vib sensor app on my phone as well, my vibrations are third order 40 Hz at 75 MPH. Not nearly as bad as many videos I've seen but annoying none the less they come and go depending on temperature, weight in the bed and I think phasing plays a role as well but they fall below GM's acceptable limit so the dealer won't do anything.

 

 

[evlwhtman]

Just took my 2015 Silverado Z71 in today for the airbag recall and the infamous chevy shake. Since purchase and the begining of the "shake" i have installed 20" denali wheels with bfg all terrain t/a's still have the "shake". I asked the dealer if installing dual exhaust would void my warranty and they said no, but now it conveniently seems to be a problem since they cant figure out what the vibration is. The service manager tells me that the outlaw flow master exhaust I installed on my truck is creating a backpressure issue causing the vibration, lol....exhaust causing a chassis issue I don't think so. So he tells me until I put the truck back to completely stock they will not work on it or call a gm engineer in to look at it. He also tells me the engineer will say that the truck has been modified and will not look at it because of the flowmasters and replacement wheels and tires I put on it. Crock of !@#$, and nothing but excuses.

[bert wise]

The hubs are not lug centric and the wheels center on the pilot which I found to be right on the money however what is strange GM used lug centric style lug nuts that will pull the wheel in one direct but only as far as the clearance between the rim and pilot will allow.

 

 

 

Just trying to educate myself here but what are the downsides to using "non-lug centric" style lug nuts to prevent pulling the wheel off center to the hub?

 

Thanks

 

Bert

Edited September 30, 2016 by bert wise

[Jesse Davidson]

Just took my 2015 Silverado Z71 in today for the airbag recall and the infamous chevy shake. Since purchase and the begining of the "shake" i have installed 20" denali wheels with bfg all terrain t/a's still have the "shake". I asked the dealer if installing dual exhaust would void my warranty and they said no, but now it conveniently seems to be a problem since they cant figure out what the vibration is. The service manager tells me that the outlaw flow master exhaust I installed on my truck is creating a backpressure issue causing the vibration, lol....exhaust causing a chassis issue I don't think so. So he tells me until I put the truck back to completely stock they will not work on it or call a gm engineer in to look at it. He also tells me the engineer will say that the truck has been modified and will not look at it because of the flowmasters and replacement wheels and tires I put on it. Crock of !@#$, and nothing but excuses.

yes, they will use anything and everything to blame it on. Thankfully all of the accessories on my truck are factory and were done by the dealer at time of sale.

 

Everything listed here has been brought up in the past as well. Somewhere in the 650 pages of posts. I personally brought up all the same points and measured runout on everything. Found runout issues with the hub stud center but at the time new hub assemblies were not readily available and were expensive. To fix the front runout issues requires a complete new assembly to fix the rear requires new axle shafts and I couldn't convince myself to spend the money for one reason, The hubs are not lug centric and the wheels center on the pilot which I found to be right on the money however what is strange GM used lug centric style lug nuts that will pull the wheel in one direct but only as far as the clearance between the rim and pilot will allow. i keep coming back to the hubs as well but haven't convinced myself to replace them because I'm not sure a new assembly will have any better tolerances than the ones on the truck right now. For the rear I looked at new shafts from Yukon 275 dollars each plus the labor to open the diff and unclip them which also means new gear oil making the whole endeavor somewhat expensive and time consuming. Attached is picture I took after measuring runout. The green line is the high point for the stud circle at .010" I used my mititoyo dial indicator with .0005" resolution to make the measurements. If you look closely you will see a pink line right next to the green, that pink line was there from the factory. This tells me GM knows these trucks are sensitive and shake and they are trying to minimize it before it leaves the factory by finding runout and trying to match low spots on the wheel assembly with the high spots on the hub to minimize the overall assembly runout. I'd be interested to know what you find if you measure yours and if you ultimately change hubs if it fixes the issue. Good luck. BTW I used the vib sensor app on my phone as well, my vibrations are third order 40 Hz at 75 MPH. Not nearly as bad as many videos I've seen but annoying none the less they come and go depending on temperature, weight in the bed and I think phasing plays a role as well but they fall below GM's acceptable limit so the dealer won't do anything.

 

 

did you see the post below?

 

Well my vibration is completely gone. Was tires of the dealership excuse. So I decided to try a few things myself. I started with swapping CV axles with new ones from the parts store. No change so I returned them. Then I replaced the drivers side hub assembly(wheel bearing) And all I have to say is POOF it's gone. Rides smoother then new.

 

 

Sent from my iPhone using Tapatalk

[Willyone]

Just took my 2015 Silverado Z71 in today for the airbag recall and the infamous chevy shake. Since purchase and the begining of the "shake" i have installed 20" denali wheels with bfg all terrain t/a's still have the "shake". I asked the dealer if installing dual exhaust would void my warranty and they said no, but now it conveniently seems to be a problem since they cant figure out what the vibration is. The service manager tells me that the outlaw flow master exhaust I installed on my truck is creating a backpressure issue causing the vibration, lol....exhaust causing a chassis issue I don't think so. So he tells me until I put the truck back to completely stock they will not work on it or call a gm engineer in to look at it. He also tells me the engineer will say that the truck has been modified and will not look at it because of the flowmasters and replacement wheels and tires I put on it. Crock of !@#$, and nothing but excuses.

 

Indeed!! This doesn't surprise me at all. I picked my '16 Z71 up on 8/17 and it now has about 900 miles on it. It's been to the dealer once for the shake and goes back for round 2 on 10/5....can't wait.... I've been wanting to put mud flaps from Weathertech, maybe a leveling kit and custom wheels on the truck, but won't do or put squat on it because I'm sure anything other than stock will give GM an excuse to weasel out of the vibe issue.

Edited September 30, 2016 by Willyone

[Willyone]

Question... is there a bulletin from GM advising of the vibration problem? I've read thru much of the thread and haven't seen if there is one or not. Sorry, I might'a missed it.

[abominable z71]

 

Just trying to educate myself here but what are the downsides to using "non-lug centric" style lug nuts to prevent pulling the wheel off center to the hub?

 

Thanks

 

Bert

The wheels are not machined for a flat lug nut and the clearances are between the stud holes in the rim are too large. Put a wheel on the hub without lug nuts and rotate it back and forth, there is nothing to take up that slop you feel using a lug nut that's not lug centric you rely completely on the normal force and friction between the face of the rim and the lug nut itself and because the rim is machined for lug centric there isn't a whole lot of surface area for a flat lug to tighten up against.

[abominable z71]

yes, they will use anything and everything to blame it on. Thankfully all of the accessories on my truck are factory and were done by the dealer at time of sale.

 

did you see the post below?

 

Yeah after seeing his post I started considering replacing the hubs again. I did something similar with the front drive shafts except i removed them completely to eliminate them as a possible source but stopped there. I couldn't convince myself to buy a 200 dollar front hub assembly but I'm reconsidering. Hard to buy a part from GM when you know the parts they make and install are of suspect quality control to begin with.

[LongrangeLauber]

Yeah after seeing his post I started considering replacing the hubs again. I did something similar with the front drive shafts except i removed them completely to eliminate them as a possible source but stopped there. I couldn't convince myself to buy a 200 dollar front hub assembly but I'm reconsidering. Hard to buy a part from GM when you know the parts they make and install are of suspect quality control to begin with.

Get a Moog or Timken bearing, should be the same front hubs from 99 and up from the looks of them

[Tim Clark]

(After two different road force and spin balances and having one of the tires replaced, I still have the following:

 

*Very noticable buzzing\vibration in the steering wheel\gas pedal while in the 45-55 mph range

 

*Front seats\console shake while in the 74-80 mph range. I can't say for sure if it goes away above 80 because it has been hard to test a speed that high (traffic/cops, etc.)

 

HOW CAN SO MANY SILVERADOS HAVE THESE ISSUES? Early 14's, late 14's, 15's...

 

I have a hard time believing that it is just tires, driveshafts or rear pinions/gear/teeth related, since it is so wide spread; as mentioned earlier, it's almost as if these trucks are super duper sensitive to any imperfection (tire, driveshaft balance, rear end, suspension, etc.).

 

Is it possible there is NO actual fix for most of us?

 

I am extremely hesitant to have a dealer with half a brain to throw parts and replacements at me, especially when they don't know the things discussed on this thread forum.

 

I am so sick of being sick of this truck. SO much to love about it too.) quote

 

I have the identical problems at the exact same speeds... My truck has been in the shop 51 days as of today and still not fixed. I have only owned it for 5 months. I put more miles on the loaners than my own truck...

Edited October 1, 2016 by Rambone71

[Snoringbear]

"I am so sick of being sick of this truck. SO much to love about it too."

 

I think you've got the makings of a great country western song started! Go for it, lol

[Britt Lifsey]

I am so sick of being sick of this truck. SO much to love about it too.

I think you've got the makings of a great country western song started! Go for it, lol

But it won't be the perfect country and western song if it doesn't say anything about mama, or trains, or prison, or getting drunk... :-)

Edited October 1, 2016 by blifsey

[C6Bill]

Don't forget a dog and a gun, got to have those for a good song !!!!!